Set theory is the primary mechanism for ideological and theoretical unification in modern mathematics. By offering a clear statement of basic questions and problems in this volume, Stephen Pollard aims to make the study of the philosophy of set theory less anarchic. Pollard largely ignores intuitionist and constructive alternatives to the Cantorian/Zermelian tradition. He applies mathematical structuralism and mathematical applications of plural reference and plural quantification - the two most important strands in the current philosophy of mathematics - to the philosophical interpretation of set theory. This book is intended to be accessible to graduate students and advanced undergraduates who have some aptitude at mathematical reasoning and some prior exposure to symbolic logic. It is suitable as a source of supplementary readings in a course on set theory or as a central text in a course on the philosophy of mathematics. It will also be of interest to professional philosophers both inside and outside of the philosphy of mathematics, and to set theorists with philosophical inclinations.